邻近城市土壤重金属对九龙江口沉积土壤的影响

在研究建立于漳州地区生态地球化学调查基础上，对河口湾沉积物的重金属与人口高度集中的城市地区土壤重金属的分布特征进行了对比，分析了人为活动对河口的影响，结果表明，城区与河口湾表层样品都舍有相对区域基准值较高的Hg、Cd，而且Hg富集系数要远高于Cd的富集系数。分析两种元素来源与迁移方式可知，Hg由于可通过气态形式迁移而对河口影响更大。城区与河口湾样品的重金属进行聚类分析与主因子分析结果表明：城区土壤的As、Zn、Mo、Ni、Cr和Mn主要来自基岩来源。Pb、Se、Cd可以作为人为污染的指示元素，Hg、Sn显示与其他元素具有相对独立的行为。河口湾的元素组合与城区重金属基本相似，但Pb、Cu、Se、Mo、Cd显示出两种因素都有较大影响，可以指示人为影响与基岩源的双重作用。

Influence of Heavy Metals in Upstream Urban Soils on Jiulong Estuary

Estuarine systems adjacent to urban areas are at risk of contamination by contaminants from anthropogenic sources,such as heavy metals.Zhangzhou is the main city nearest Jiulong estuary,and the Jiulong River runs through Zhangzhou City.The present study is based on a preliminary geochemistry survey on Zhangzhou areas and aims at comparing heavy metals from the estuary sediments with more densely populated city soils.Topsoil samples from urban and estuary have higher Hg and Cd concentrations compared with regional mean values.The estuary has higher EF for Hg than Cd.Hg from Zhangzhou urban areas has strong influence on Jiulong estuary.Based on results of clustering analysis and principal component analysis,As,Zn,Mo,Ni,Cr,and Mn are inferred to derive from lithogenic inputs.Pb,Se and Cd can be identified as a tracer of anthropogenic pollution for samples from urban and periurban.Hg and Sn show independence of other elements.Heavy metals in the estuary are similar to those in the urban area except Pb,Cu,Se,Mo,and Cd that are high by two factors,suggesting both lithogenic and anthropogenic sources.